Tank with breather opening in fill pipe



Jan. 3, 1950 F. P. SCULLY TANK WITH BREATHER OPENING IN FILL PIPE Filed001,. l, 1947 incorporated "tially as the liquid in the body PatentedJan. 3, 1950 UNiITED STATES PATENT OFFICE TANK WITH BREATHE-R OPENING INFILL PIPE Frank P. v Scully, Belmont, Mass, assignor to Scully SignalCompany, East Cambridge, Mass, a corporation of MassachusettsApplication October 1, 1947, Serial No. 777,210 "1 Claims. (01. 116-109)'1 This invention relates to fuel tanks that have therein gas-operatedsignaling means for indicating when the rising liquid level 'has reacheda predetermined point. The invention is particularly concerned withgasoline tanks on automobiles, but may be used with equal effectivenessin any situation where the tank is subject to movement to cause surgingof the liquid therein.

Audible signaling devices of the type used in connection with thepresent invention are shown, for example, in the reissue patent toMathey, No. 22,391 A modification of this type or construction is alsoshown in the patent to Scully ct a1., No. 2,323,156. In general, it maybe said that invention is devised for use with a gasoline tank in whicha gas-"operated signaling device is positioned within and close to thetop of the tank or has a portion extending through the top into the tankand in which the vent pipe leading from the signaling device term-inatesat a point within the fill pipe, formin .a closed system when the capcloses the fill pipe, and in which means is provided to cause gasdisplaced by entering liquid to flow through the signaling device on itsway to the atmosphere.

In installations or this sort, where the fill pipe is of the so-calleddeep fill type, that is, where the inner end of the fill pipe extends toa position below the liquid level so that displaced gas cannot escapethrough the fill pipe and the undesirable splashing that would otherwiseoccur is eliminated, an objectionable feature has been noticed.

Let us assume that the tank is half full, with the automobile in normaloperation. The usual cap will close the upper end of the fill pipe sothat there is no free iiow of gas into the tank from the atmosphere. Asthe vehicle moves,

the liquid will surge about in the tank, and the liquid level within thepipe will vary substanoi the tank surges from one side to the other. Theresult of this liquid movement is that there is a constant back andforth movement of gas through the whistle; that is, as the liquid risesin the ii ll pipe, the pressure on the vent pipe side of "the whistleincreases, while the pressure on the gas in the tank drops. Thus thereis a quick movement of air from the fill pipe down through the ventpipe, through the whistle, and into the tank. This causes a short butdistinctly audible sound. Conversely, as the liquid surges in theopposite direction :so that the level in the fill pipe drops, then therea quick surigeoi air upwardly 2 through the whistle through the ventpipe and into the filler neck, again causing an audible sound. The netresult of this circumstance is that in a moving automobile having asignaling system of this nature there will be produced a succession ofshort audible sounds that have no relation to the liquid level.

When the gasoline tank is located in proximity to the driver orpassengers, this steady sounding of the whistle is objectionable, andtherefore it is an object of the present invention to overcome thissituation without otherwise impairing or interfering with the normaloperation of the signal during filling.

The invention Will be more fully described. hereinafter with the aid ofthe accompanying drawings, in which Fig. 1 .is a vertical sectional viewof a tank, a fill pipe, and a signaling device, with the latter being inelevation, The several elements are broken away in part.

Fig. 2 is a view of a section of the fill pipe apart from the tank,viewed from its under side along the line 2-'2 of Fig. '1.

Fig. 3 is a sectional view of the fill pipe along the line 3-3 of Fig.2.

Fig. 4 is a vertical sectional view of the signaling means and a shortsection of the vent pipe extending therefrom.

Referring to Fig. 1, there is shown a typical gasoline tank 2 having afill pipe 4, the lower end of which extends to a position close to thebottom of the tank to provide a typical deep fill installation. Theupper end of the fill pipe, except during filling, .is normally closedby a cap 8. This cap has the usual small vent 9 therethrough so that nonegative pressure condition can develop in the tank as the gasoline isconsumed. However, the opening through the cap is so small that gascannot flow in or out freely enough to offset at once any quick pressurechanges that may develop in the fill pipe.

Positioned on the top of the tank at any convenient place is thesignaling means HI. This consists of a housing I? having a horizontalflange M which is secured to the tank top in any convenient airandliquid-tight manner. A vent pipe "l6 connected by a short nipple l8extending from one side of the housing leads into the fill pipe near theupper end of the latter at position 2|].

side of the whistle depends an intrusion tube 28 passing through a hole30 in the top of the tank. Hole 30 is somewhat larger than intrusiontube 28 so that in the event of a pressure de veloping in the tank whichmight drive Whistle 22 upwardly from its seat, part of the gas may bebypassed through opening 30 to the vent pipe [6.

At the point where fill pipe 4 passes through and is in engagement withthe tank as at 32, a rigid airand water-tight connection is effected.This may be by soldering, welding or in any other convenient manner.Immediately below the point of connection and within the tank, anopening 34 is provided through the wall of vent pipe 4. The nature ofthis opening is clearly shown in Figs. 1, 2 and 3. In practice it can beeasily made by sawing a limited transverse slot 36 through the fill pipewall and thenforcing the wall inwardly to form a reversely curvedinterior blister 38, with the open side in the direction'of the lowerend of the pipe.

The opening so formed will hereinafter be referred to as the breatherslot. While it is shown positioned on the under side of the fill pipe 4,it is to be understood that it may be located any place about the tubescircumference. The object of the breather slot is to eliminate anychange in pressure in the upper part of the fill pipe 4 so long as thelevelof the liquid is below the breather slot. Thus, while stillobtaining the advantages of the deep fill, nevertheless theobjectionable back and forth passage of air through V the whistle due tosurging of liquid in the tank'is eliminated, provided the liquid levelis below the breather slot. It has been found the the objectionablewhistling occurs almost entirely when the tank is less than half full.This is due to the fact that the liquid in' a partially filled tank willsurge more than in a full tank. Consequently, the

low level liquid will run further up the fill pipe on each surge. As thetank becomes more nearly full, surging is reduced, and there is lessmovement of air through the whistle and hence less sound.

In any event, the breather slot 34 as disclosed is located high enoughto eliminate the objectionable characteristic; By placing the breatherslot on the top side of the tube at 39 where it would be substantiallyon a level with the lower end of :intrusion tube 28, then the level maybe raised correspondingly before the breather slot is sealed. Theoperation of the invention is as follows:

.,'The filler cap 8 is removed, and liquid is fed into the tank in theusual manner. somewhat restricts the cross-sectional area of fill pipe 4so that the liquid flowing thereover acts The blister 38 as a seal toprevent any escape of displaced gas through thebreather slot. Since thesubmerged part of the fill pipe is also effectively sealed by "liquid,all displaced gas must flow through the signaling unit and vent pipe Hito the upper end of the fill pipe, and thence to the atmosphere.

In normal filling, the liquid supply would be out 65 off when the levelhas reached a point a little above the lower end of intrusion tube 28.Thereamounts to cause objectionable sounding. Finally, however, theliquid is consumed to such an' -fill pipe and breather slot on one sideand the whistle on the other side, is the same as the tank pressure. Ifthe liquid then surges so that the level rises in the fill pipe but doesnot reach the breather slot, the tank and fill-pipe pressures willimmediately come into balance through movement of gas through thebreather slot plus an inaudible slight .movement through the whistle.

Conversely, as the liquid surges in the opposite direction and the levelin the fill pipe falls, any change in pressure between the tank and ventpipe I6 is again adjusted by gas flow through the breather slotsufiicient to prevent sounding of the whistle. In this way, all soundwhich would otherwise be caused by surging of the liquid issubstantially eliminated.

It should also be noted that the form of the blister 38 not onlyprevents the escape of gas therethrough during filling, since the liquidpassing thereover acts as a seal, but also substantially eliminates anyentrance of gasoline to the tank through breather slot 34. In. this way,in spite of the breather slot, all the benefits of the deep fill areretained. It will be understood, of course, that there may be someslight dripping of liquid into the tank from breather slot 34 duringfilling, but such amounts will be negligible and cannot be considered asinterfering in any way with the deep fill principle.

While the invention has been shown and described by reference to apreferred form of the invention, it is to be understood that it is notto be limited thereby but only by the appended claims.

I claim:

l. The combination of a tank, a fill pipe having a deep fillextension'within said tank, a gasoperated audible signaling devicehaving its gas receiving end positioned within and near the top of saidtank and operable to give a distinctive sound during the filling of saidtank as displacedgas flows through said device as the liquid levelrises, said device operable to cause cessation of said distinctive soundto give an indication when the liquid has risen to a predeterminedlevel, a vent pipe leading from said signaling device to a point in saidfill pipe high- .er than the top of said tank, and a breather openingthrough said fill pipe at a point within and a substantial distanceabove the bottom of said tank, whereby, as liquid whose level is belowthe level of said opening. surges in said tank, pressure in said tankand said vent pipe will differ an amount insufilcient to cause normalsound producing movement of gas through said signaling device.

2. The combination set forth in ,claim 1, in which said breather openingis located in said fill pipe at a point above the half-filled level.

3. The combination set forth in claim 1, in whichsaid breatheropening'faces in the direction of flow of entering liquid, wherebyentering liquid will flow past said opening to enter said tank throughsaid deep fill extension.

4. The combination set forth in claim 1, in which said breather openingis shielded from entering liquid by a member extending inwardly of saidpipe, which member causes entering liquid to flow over and past saidbreather opening to prevent the escape of displaced gas through saidopening during filling.

5. The combination set forth in claim 1, and means for substantiallypreventing the flow of entering liquid into said tank through saidopening.

6. The combination set forth in claim 1, in which said pipe has been cuttransversely, and that portion of the pipe on the outer side of said outhas been bent inwardly of said pipe, said opening bounded in part by thedistorted edge of said cut.

7. The combination of a tank, fill pipe having a deep fill extensionwithin said tank, a

gas operated audible signaling device positioned adjacent to the top ofsaid tank and operable to give a distinctive sound during the filling ofsaid tank as displaced gas flows through said device as the liquid levelrises, said device comprising means for controlling the operation ofsaid device to indicate through the auditory senses when the liquid hasrisen to a predetermined level, a vent pipe leading from said signalingdevice to a point in said fill pipe higher than the top of said tank,and a breath- No references cited.

